JP7213436B2 - STRESS CHARACTERISTICS MEASURING METHOD, STRESS CHARACTERISTICS MEASURING DEVICE, AND STRESS CHARACTERISTICS MEASURING SYSTEM - Google Patents

Description

The present disclosure relates to a stress property measuring method, a stress property measuring device, and a stress property measuring system.

Patent Literature 1 discloses a method of measuring the stress distribution generated in a structure that has two support parts and a beam part provided between each support part due to the movement of a moving body. It is This method comprises the steps of capturing an image of a moving body by a first capturing unit or capturing an identification display attached to a structure from the moving body to generate first image data; obtaining a movement period during which the beam moves between the support parts of the structure; photographing the surface of the beam part of the structure with a second imaging part to generate second image data; and moving period in the thermal image data and a step of calculating a stress change based on the temperature change and obtaining a stress distribution based on the stress change.

WO2017/141294

The present disclosure provides a stress characteristic measuring method, a stress characteristic measuring apparatus, and a stress characteristic measuring method, a stress characteristic measuring apparatus, and a stress characteristic measuring method for highly accurate and convenient measurement of stress characteristics for comparison of stress generated at each location of a structure in an actual site environment where the structure is arranged. A property measurement system is provided.

The present disclosure is a method for measuring characteristics of stress generated in a structure, comprising a step of acquiring a plurality of thermal images taken at different times according to the temperature of the surface of the structure from a first imaging device. a step of generating a stress distribution image corresponding to each of the plurality of thermal images; and a stress value of a first portion having a stress gradient smaller than a predetermined value in each of the stress distribution images; and using the obtained stress value of the first portion and the stress value of each of the plurality of second portions to obtain a stress value for each of the second portions of the structure and deriving correlation properties of the stress in .

Further, the present disclosure is a stress characteristic measuring device for measuring the characteristics of stress generated in a structure, wherein a plurality of heat waves captured at different times according to the temperature of the surface of the structure are received from a first imaging device. a communication unit that acquires an image; a generation unit that generates a stress distribution image corresponding to each of the plurality of thermal images; and a stress value of a first portion having a stress gradient smaller than a predetermined value in each of the stress distribution images , a selection unit that acquires the stress value of each of the plurality of second portions where stress is concentrated; and the acquired stress value of the first portion and the stress value of each of the plurality of second portions. and a calculator that derives the stress correlation characteristic in the portion of the structure using the stress characteristic measuring device.

The present disclosure also provides a stress characteristic measuring system including a stress characteristic measuring device that measures characteristics of stress generated in a structure, and a first imaging device. The stress characteristic measuring device acquires a plurality of thermal images taken at different times according to the temperature of the surface of the structure from the first imaging device, and a stress distribution corresponding to each of the plurality of thermal images. An image is generated, and in each of the stress distribution images, a stress value of a first portion having a stress gradient smaller than a predetermined value and a stress value of each of a plurality of second portions where stress is concentrated are obtained. The stress value of the first portion and the stress value of each of the plurality of second portions are used to derive a stress correlation characteristic of the portion of the structure.

Advantageous Effects of Invention According to the present disclosure, it is possible to measure, with high accuracy and convenience, stress characteristics for comparison of stress generated at each location of a structure in an actual site environment where the structure is arranged.

Situation depiction diagram showing an example of how a plurality of premises speakers are arranged on a station platform Enlarged view of essential parts showing an example of a state in which the premises speaker is fixed to the beam of the ceiling via the support bracket Situation depiction diagram showing the fixing situation of the premises speaker in front view and side view 1 is a block diagram showing a configuration example of a stress characteristic measurement system according to Embodiment 1. FIG. A diagram showing an example of stress distribution at the connecting portion between the beam portion and the support fitting when vibration occurs under the first condition. A diagram showing an example of stress distribution at the connecting portion between the beam portion and the support fitting when vibration occurs under the second condition. A diagram showing an example of stress distribution at the connecting portion between the beam portion and the support fitting when vibration occurs under the third condition. A diagram showing an example of stress distribution at the connecting portion between the beam portion and the support fitting when vibration occurs under the fourth condition. A diagram showing an example of stress distribution at the connecting portion between the beam portion and the support fitting when vibration occurs under the fifth condition. Explanatory drawing of an example of stress distribution characteristics for each of multiple positions in the joint between the beam and the support bracket 4 is a flow chart showing the operation procedure of the stress characteristic measuring device according to Embodiment 1. 4 is a flow chart showing the operation procedure of the stress characteristic measuring device according to Embodiment 1. Situation depiction diagram showing the appearance of a conventional test piece used for stress measurement in plan view and perspective view

(Circumstances leading to this disclosure)
FIG. 13 is a situation depiction diagram showing the appearance of a conventional test piece SMP1 used for stress measurement in a plan view and a perspective view. As a structure to receive the load, a cuboid (for example, length 140 mm (= 70 mm × 2), width 15 mm (= 7.5 mm × 2), thickness 3 mm) like the test piece SMP1 At the center of one side in the longitudinal direction Consider a member provided with a notch NCH1 on each side in the width direction. Note that the dimensions shown in FIG. 13 are merely examples, and the dimensions are not limited thereto.

In the stress distribution when a load is applied to the test piece SMP1, the maximum stress is applied to the portion Pt1 of the notch NCH1, and the average stress is It takes This is because stress locally increases (that is, stress concentrates) around a portion of the structure where the cross-sectional shape changes, such as a hole or notch, as in the test piece SMP1. The degree of stress concentration varies depending on the cross-sectional shape, and stress tends to increase as the change in cross-sectional shape becomes more pronounced. In FIG. 13, RA indicates the radius of curvature of the bottom of the notch NCH1, d indicates the depth of the notch NCH1, and K indicates half the width of the minimum section.

On the other hand, in a site environment where a general structure without a unique shape such as the notch described above is actually placed, a portion where stress is concentrated due to vibrations of different magnitudes caused by various surrounding factors can be inferred externally from the shape and the like. However, when vibrations of different magnitudes occur, it has been difficult to compare and determine how much stress is applied to the structure for each location. In other words, even if vibrations with different magnitudes occur, for example, it is not possible to compare the stress characteristics of each location, including locations where stress is likely to concentrate and locations where stress concentration is difficult, in the structure. However, we could not obtain an objective index to judge whether the area is more susceptible to stress than other areas.

In addition, in Patent Document 1, a thermal image is obtained when a test vehicle with a known vehicle weight travels in a predetermined measurement section on a road on a bridge (for example, a section between two adjacent piers on a road on a bridge). Data is measured, the stress distribution is determined based on this thermal image data, and a comparison is made between the stress values generated in the previous test vehicle and the calculated values of the design. However, in order to perform such a measurement, it is restricted to a limited time period such as late at night when the number of vehicles running is low, so the convenience of the measurement is not good.

In the following embodiments, a stress characteristic measuring method and a stress characteristic measuring method for measuring stress characteristics with high accuracy and convenience for comparison of stress generated at each location of a structure in an actual site environment where the structure is arranged are described. Examples of apparatus and stress property measurement systems are described.

Hereinafter, embodiments specifically disclosing the configuration and operation of the stress characteristic measuring method, the stress characteristic measuring apparatus, and the stress characteristic measuring system according to the present disclosure will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and redundant descriptions of substantially the same configurations may be omitted. This is to avoid unnecessary verbosity in the following description and to facilitate understanding by those skilled in the art. It should be noted that the accompanying drawings and the following description are provided for a thorough understanding of the present disclosure by those skilled in the art and are not intended to limit the claimed subject matter.

Hereinafter, the stress characteristic measuring method according to Embodiment 1 executes the following processes (steps). Specifically, the stress characteristic measuring method measures the characteristic of stress generated in a structure (for example, a supporting bracket for a premises speaker arranged to be fixed to the ceiling of a station platform). The stress characteristic measuring method acquires a plurality of thermal images with different imaging times according to the temperature of the surface of the structure from an infrared camera (an example of the first imaging device), and corresponding to each of the plurality of thermal images. Generate a stress distribution image. In addition, the stress characteristic measuring method acquires the stress value of a first portion having a stress gradient smaller than a predetermined value and the stress value of each of a plurality of second portions where stress is concentrated in each stress distribution image, Using the acquired stress value of the first portion and the stress values of each of the plurality of second portions, a correlation characteristic of stress in the portion of the structure is derived and output.

As described above, in the following description, as an example of the structure, the supporting metal fittings (see FIG. 1) for the premises speaker arranged so as to be fixed to the ceiling of the platform of the station will be exemplified. It is not limited to support fittings (see below).

<Layout example of structures to be measured>
FIG. 1 is a situation depiction diagram showing an example of how a plurality of premises speakers SPK1 and SPK2 are arranged on the platform of a station STA. FIG. 2 is an enlarged view of an essential part showing an example of how the premises speaker SPK1 is fixed to the beam JST1 of the ceiling via the support metal fitting SPT1 (speaker fastening metal fitting). FIG. 3 is a situation depiction diagram showing the fixing situation of the premises speaker SPK1 in front view and side view.

As shown in FIG. 1, a down train TR1 and an up train TR2 pass through the platform of the station STA. To facilitate understanding of the following description, the station STA shown in FIG. 1 is assumed to be a station where only regular trains (each stop) stop. In-house speakers SPK1 and SPK2 for outputting announcement voices to passengers and the like are suspended and fixed from the ceiling of the platform. A visible light camera 10 is suspended from the ceiling of the platform so that the train TR1 is included in the angle of view for detecting the passage of the train TR1 or monitoring passengers on the platform. Although not shown in FIG. 1, a visible light camera is suspended from the ceiling of the platform so that the train TR2 is included in the angle of view in order to detect the passage of the train TR2 or to monitor passengers on the platform. ing.

As shown in FIG. 2, the premises speaker SPK1 is suspended and fixed to the beam JST1 of the ceiling of the platform via a support fitting SPT1 screwed by three bolts V1, V2 and V3. In other words, each of the three bolts V1 to V3 screws the support fitting SPT1 of the premises speaker SPK1 to the beam JST1. However, when a train (for example, train TR1) passes through the platform of station STA, the amplitude (magnitude) differs for each timing depending on the type (for example, forwarding, express, limited express) or the number of trains passing through. Vibration occurs. In such a case, the support fitting SPT1 (an example of the structure) that supports the premises speaker SPK1 is subjected to stress according to the magnitude of the vibration accompanying the vibration. In order to make the explanation easier to understand, it is assumed that the express train and the limited express train pass at different speeds when passing through the platform of the station STA, and that the latter is faster than the former. In other words, a larger stress is applied to the support fitting SPT1 when an express train passes than when an express train passes.

In the stress characteristic measuring method according to the first embodiment, the stress characteristic measuring system 100 measures the stress characteristic of a structure (for example, the support fitting SPT1) caused by vibration whose magnitude varies depending on the situation when a train passes on the platform of the station STA. To measure, generate a thermal image of the surface of the structure using an infrared camera 20 (see FIG. 3). For example, as shown in the side view and front view of FIG. 3, a mirror MRR1 is arranged on the upper surface of the housing of the premises speaker SPK1. The infrared camera 20 captures (pictures) the mirror image of the structure reflected on the mirror MRR1 (specifically, the mirror image of the support fitting SPT1 fixed to the beam JST1 by the three bolts V1 to V3). Generate a thermal image of a structure (eg, a support bracket SPT1 containing three bolts V1-V3).

<Configuration of stress characteristic measurement system>
FIG. 4 is a block diagram showing a configuration example of the stress characteristic measurement system 100 according to the first embodiment. The stress characteristic measurement system 100, for example, when a train passes through the platform of the station STA, according to the magnitude (amplitude) of vibration caused by the situation at the time of passage, the premises speaker suspended from the ceiling of the platform. The characteristics of the stress generated in the support fitting SPT1 (an example of the structure) for supporting are measured. The stress characteristic measuring system 100 includes a visible light camera 10 , an infrared camera 20 and a stress characteristic measuring device 30 .

A visible light camera 10 as an example of the second imaging device is arranged, for example, suspended from the ceiling of the platform of the station STA (see FIG. 1). The visible light camera 10 shoots at a predetermined frame rate (for example, 60 fps) at a fixed angle of view (for example, an angle of view including train TR1 or passengers passing by train TR1) at the time of installation to obtain visible image data of the subject. is generated and sent to the stress characteristic measuring device 30 .

An infrared camera 20 as an example of the first imaging device is arranged, for example, suspended from the ceiling of the platform of the station STA (see FIG. 3). The infrared camera 20 shoots at a predetermined frame rate (eg, 60 fps) at an angle of view fixed at the time of installation (for example, an angle of view at which the supporting metal fitting SPT1 including the three bolts V1 to V3 can be captured as an object, see FIG. 3). Then, thermal image data of the subject is generated and sent to the stress characteristic measuring device 30 .

The stress characteristic measuring device 30 acquires a thermal image of a structure (for example, a support fitting SPT1 including three bolts V1 to V3) based on visible image data from the visible light camera 10 or sensing result data from the sensor 40. A shooting period from the start of shooting to the end of shooting is specified. Also, based on the thermal image data of the subject captured during the imaging period, the stress distribution and stress characteristics generated in the structure (the support fitting SPT1 including the three bolts V1 to V3) are measured. The stress characteristic measuring device 30 transmits the respective data of stress distribution and stress characteristic to a server (not shown) or the like via the Internet 2 .

The sensor 40 is arranged, for example, suspended from the ceiling of the platform of the station STA (not shown). The sensor 40 detects, for example, the platform of the train TR1 at predetermined intervals based on the presence or absence of reflection of the infrared rays emitted into a predetermined area on the platform (for example, the position where the train TR1 enters the platform) set at the time of installation. The presence or absence of an incoming wire is sensed, and data of the sensing result is generated and sent to the stress characteristic measuring device 30 .

The configuration of the stress characteristic measuring device 30 will be described in detail below.

The stress characteristic measuring device 30 includes a first communication unit 31, a second communication unit 32, a third communication unit 33, a memory 34, a processor 35, a display unit 36, an operation unit 37, and a 4 and a communication unit 38 are included.

The first communication unit 31 is configured by a communication interface such as USB (Universal Serial Bus), HDMI (High-Definition Multimedia Interface) (registered trademark), or the like. The first communication unit 31 is an input unit that sequentially inputs data of a visible image of a subject captured at a predetermined frame rate from the visible light camera 10 .

The second communication unit 32 is configured by a communication interface such as USB, HDMI (registered trademark), or the like. The second communication unit 32 is an input unit that sequentially inputs thermal image data of a subject captured at a predetermined frame rate from the infrared camera 20 . The second communication unit 32 also receives control information regarding the operation of the infrared camera 20 such as start and end of imaging from the processor 35 and transmits the received control information to the infrared camera 20 .

The third communication unit 33, for example, IEEE (Institute of Electrical and Electronics Engineers) 802.11, 3G (third generation mobile communication system), 4G (fourth generation mobile communication system), 5G (fifth generation mobile communication system) ) and other communication standards. A third communication unit 33 connects the processor 35 and the Internet 2 .

The memory 34 is configured using, for example, a RAM (Random Access Memory) and a ROM (Read Only Memory), and stores programs necessary for executing the operation of the stress characteristic measuring device 30, and data or information generated during the operation. is stored temporarily. The RAM is a work memory used when the processor 35 operates, for example. The ROM stores in advance a program for controlling the processor 35, for example.

Moreover, the memory 34 may have a recording medium constituted by, for example, an HDD (Hard Disk Drive) or an SSD (Solid State Drive), in addition to the RAM and ROM described above as the physical configuration. The memory 34 stores the data of the visible image of the subject captured by the visible light camera 10 and received via the first communication unit 31 . In addition, the memory 34 stores thermal image data of a subject that is captured by the infrared camera 20 and received via the second communication unit 32 . The memory 34 also stores reference values input from an operation unit 37 (to be described later), which are necessary for the processor 35 to specify the timings at which the infrared camera 20 starts and ends capturing of thermal images. .

The memory 34 also stores a risk presentation table showing the correspondence relationship between the stress characteristics (inclination, see FIG. 10) at points (locations) in the structure derived by the processor 35 and the risk information at the points (locations). (not shown) is stored. This risk presentation table is defined in advance as predetermined design information before starting the actual operation of the stress characteristic measurement system 100 . Further, the memory 34 stores an improvement measure presentation table (not shown) showing the relationship between risk information and improvement measures for structures (for example, technical countermeasures such as repair and repair). This improvement measure presentation table is defined in advance as default design information before starting the actual operation of the stress characteristic measurement system 100, but if necessary, the user can add, change, Updates such as deletion may be made.

The processor 35 is configured using, for example, a CPU (Central Processing Unit), a DSP (Digital Signal Processor), or an FPGA (Field Programmable Gate Array). The processor 35 functions as a control unit of the stress characteristic measuring device 30, performs control processing for overall control of the operation of each unit of the stress characteristic measuring device 30, and performs data input to and from each unit of the stress characteristic measuring device 30. It performs output processing, data arithmetic processing, and data storage processing. Processor 35 operates according to a program stored in memory 34 .

For example, the processor 35 controls operations of the infrared camera 20 such as start and end of photographing. Based on the visible image data from the visible light camera 10 or the sensing result data from the sensor 40 , the processor 35 identifies the timing at which the infrared camera 20 starts or ends capturing of the thermal image. The processor 35 measures the stress distribution generated in the structure (for example, the support fitting SPT1 including the three bolts V1 to V3) based on the thermal image data captured by the infrared camera 20 based on the specified timing. do.

A method for obtaining the stress distribution from thermal image data is, for example, the following method.

(1) When the processor 35 acquires the data of the thermal image sent from the infrared camera 20, it obtains the temperature variation over time for each pixel of the thermal image as the temperature variation. For example, the processor 35 obtains the temperature change amount by Fourier transforming the thermal image data.

(2) The processor 35 obtains the stress distribution based on the obtained temperature variation. Specifically, the processor 35 obtains the stress change amount over time for each pixel of the thermal image as the stress change amount based on the temperature change amount. For example, the processor 35 calculates the amount of stress change Δδ from the amount of temperature change ΔT using Equation (1) representing the thermoelastic effect.

In Equation (1), K is the thermoelastic coefficient, K=α/(ρCp). T is the absolute temperature of the structure (eg, the support bracket SPT1 including the three bolts V1-V3). α is the linear expansion coefficient of the structure, ρ is the density of the structure, and Cp is the specific heat under constant stress. The processor 35 generates a stress distribution image by determining the stress distribution based on the amount of stress change for each pixel that constitutes the thermal image. Processor 35 is an example of a generator.

In addition, the processor 35 stores a plurality of images of the measured stress distribution (specifically, stress distributions based on individual thermal images captured when vibrations having different magnitudes (amplitudes) are generated. The images (see FIGS. 5-9)) are used to generate the stress profile of the structure (see FIG. 10). The processor 35 transmits the image data of the stress distribution of the structure or the data of the stress characteristic of the structure measured when each vibration occurs to an external server or the like via the Internet 2 .

The display unit 36 is composed of, for example, a liquid crystal display or an organic EL (Electroluminescence) display, and displays the stress distribution image data or stress characteristic data measured by the processor 35 as color information or gradation information, for example.

The operation unit 37 is composed of, for example, a keyboard, a touch panel, buttons, and the like. The operation unit 37 is operated by the user when setting a reference value necessary for detecting the timing at which the infrared camera 20 starts and ends capturing of a thermal image.

The fourth communication unit 38 is, for example, IEEE802.11, 3G (third generation mobile communication system), 4G (fourth generation mobile communication system), 5G (fifth generation mobile communication system) and other communication standards. Consists of a communication interface. A fourth communication unit 38 connects the sensor 40 and the processor 35 .

Next, examples of stress distribution images and stress characteristic data generated by the stress characteristic measuring apparatus 30 according to the first embodiment will be described with reference to FIGS. 5 to 10, respectively.

FIG. 5 is a diagram showing an example of stress distribution at the connecting portion between the beam portion JST1 and the support fitting SPT1 when vibration occurs under the first condition. FIG. 6 is a diagram showing an example of stress distribution at the connecting portion between the beam JST1 and the support metal fitting SPT1 when vibration occurs under the second condition. FIG. 7 is a diagram showing an example of stress distribution at the connecting portion between the beam portion JST1 and the support fitting SPT1 when vibration occurs under the third condition. FIG. 8 is a diagram showing an example of stress distribution at the connecting portion between the beam portion JST1 and the support fitting SPT1 when the fourth condition vibration occurs. FIG. 9 is a diagram showing an example of stress distribution at the connecting portion between the beam portion JST1 and the support fitting SPT1 when vibration occurs under the fifth condition. FIG. 10 is an explanatory diagram of an example of stress distribution characteristics at each of a plurality of positions in the connecting portion between the beam JST1 and the support fitting SPT1.

As shown in FIG. 10, the stress characteristic measuring apparatus 30 according to the first embodiment measures a plurality of stress characteristics generated based on thermal images captured when vibrations having different magnitudes (amplitudes) occur. Within the image of the distribution, stress values (pixel values) are extracted at four different points (specifically, points A, B, C, and D) in the structure shown in each image. In Embodiment 1, conditions 1 to 5 are exemplified as conditions under which vibrations having different magnitudes (amplitudes) are generated in a structure. The stress characteristic measuring device 30 selects points A to Each stress value of D is used to derive the stress profile (see FIG. 10).

For example, as shown in FIG. 5, the stress distribution image CPG1 is generated based on the thermal image of the connecting portion (see above) captured by the infrared camera 20 when the first condition vibration occurs. Here, the vibration of the first condition occurs in the structure (for example, the support fitting SPT1 including three bolts V1 to V3) among the five conditions (first to fifth conditions) exemplified in the first embodiment. This is the vibration with the smallest magnitude (amplitude) of the vibration to be applied. For example, the vibration of the first condition is the vibration generated until the outbound train TR1 (train TR2) of the forwarding type (train TR2) in the down direction (or up direction is also possible) has passed the platform of the station STA shown in FIG. In order to make the explanation easier to understand, it is assumed that the passing speed when passing the platform of the station STA is faster in the order of forwarding type trains, express type trains, and limited express type trains. According to the image CPG1 shown in FIG. 5, among the three bolts V1 to V3, the stress value is the minimum value at the point D (first portion, an example of a flat portion) near the center bolt V2, and the stress value is the minimum value at the bolt V1 at both ends. , V3 near points A, B, and C (an example of the second portion), the respective stress values are local maximum values (maximum values) compared to the stress value at point D. FIG.

For example, as shown in FIG. 6, the stress distribution image CPG2 is generated based on the thermal image of the connecting portion (see above) captured by the infrared camera 20 when the vibration under the second condition occurs. Here, the vibration of the second condition occurs in the structure (for example, the support fitting SPT1 including three bolts V1 to V3) among the five conditions (first to fifth conditions) exemplified in the first embodiment. It is the second smallest vibration in magnitude (amplitude). For example, the vibration of the second condition is the vibration generated until the train TR1 (train TR2) of the express type in the down direction (or up direction is also possible) has passed the platform of the station STA shown in FIG. According to the image CPG2 shown in FIG. 6, the stress value is the minimum value at point D (an example of a flat portion) near the center bolt V2 among the three bolts V1 to V3, and the stress value near the bolts V1 and V3 at both ends At points A, B, and C, the respective stress values are local maximum values (maximum values) compared to the stress value at point D. Also, in the image CPG2 shown in FIG. 6, the stress values of the points A, B, and C are larger than the stress values of the points A, B, and C in the image CPG1 shown in FIG. ing.

For example, as shown in FIG. 7, the stress distribution image CPG3 is generated based on the thermal image of the connecting portion (see above) captured by the infrared camera 20 when the vibration under the third condition occurs. Here, the vibration of the third condition occurs in the structure (for example, the support fitting SPT1 including three bolts V1 to V3) among the five conditions (first to fifth conditions) exemplified in the first embodiment. The magnitude (amplitude) of the vibration that occurs is the third smallest. For example, the vibration of the third condition is the vibration generated until the outbound (or inbound) limited express train TR1 (train TR2) finishes passing the platform of the station STA shown in FIG. According to the image CPG3 shown in FIG. 7, the stress value is the minimum value at point D (an example of a flat portion) near the center bolt V2 among the three bolts V1 to V3, and near the bolts V1 and V3 at both ends. At points A, B, and C, the respective stress values are local maximum values (maximum values) compared to the stress value at point D. Also, in the image CPG3 shown in FIG. 7, the stress values of the points A, B, and C are larger than the stress values of the points A, B, and C in the image CPG2 shown in FIG. ing.

For example, as shown in FIG. 8, the stress distribution image CPG4 is generated based on the thermal image of the connecting portion (see above) captured by the infrared camera 20 when the fourth condition vibration occurs. Here, the vibration of the fourth condition occurs in the structure (for example, the support fitting SPT1 including three bolts V1 to V3) among the five conditions (first to fifth conditions) exemplified in the first embodiment. It is the vibration with the second largest magnitude (amplitude) of vibration. For example, the vibration of the fourth condition is the vibration generated until the outbound and inbound express trains TR1 and TR2 finish passing through the platform of the station STA shown in FIG. According to the image CPG4 shown in FIG. 8, the stress value is the minimum value at point D (an example of a flat portion) near the center bolt V2 among the three bolts V1 to V3, and near the bolts V1 and V3 at both ends. Of the points A, B, and C, the stress values at points A and C in particular are local maximum values (maximum values) compared to the stress value at point D. Also, in image CPG4 shown in FIG. 8, the stress values of points A, B, and C are larger than the stress values of points A, B, and C in image CPG3 shown in FIG. ing.

For example, as shown in FIG. 9, the stress distribution image CPG5 is generated based on the thermal image of the connecting portion (see above) captured by the infrared camera 20 when the vibration under the fifth condition occurs. Here, the vibration of the fifth condition occurs in the structure (for example, the support fitting SPT1 including three bolts V1 to V3) among the five conditions (first to fifth conditions) exemplified in the first embodiment. This is the vibration with the largest magnitude (amplitude). For example, the vibration of the fifth condition is the vibration generated until the outbound and inbound limited express trains TR1 and TR2 finish passing the platform of the station STA shown in FIG. According to the image CPG5 shown in FIG. 9, of the three bolts V1 to V3, the stress value is the minimum value at the point D (an example of the flat portion) near the central bolt V2, and the stress value near the bolts V1 and V3 at both ends. Of the points A, B, and C, the stress values at points A and C in particular are local maximum values (maximum values) compared to the stress value at point D. Also, in image CPG5 shown in FIG. 9, the stress values of points A, B, and C are larger than the stress values of points A, B, and C in image CPG4 shown in FIG. ing.

As described above, the stress characteristic measuring apparatus 30 according to the first embodiment can determine the vibration generation conditions from the data of the plurality of stress distribution images obtained when the vibrations shown in FIGS. 5 to 9 are generated. Using the stress values for each of points AD, the stress characteristics are derived (see FIG. 10). In FIG. 10, the horizontal axis of the stress characteristic graph indicates the stress [MPa] at a flat portion such as point D of the stress distribution images (eg, images CPG1 to CPG5). The vertical axis of the stress characteristic graph indicates stress [MPa] at points where stress is likely to concentrate, such as points A, B, and C of stress distribution images (eg, images CPG1 to CPG5). Points A, B, and C are locations where the housing of the premises speaker SPK1 is supported in a state in which the support metal fitting SPT1 is suspended from the beam JST1, so stress is more likely to be concentrated than at point D due to the occurrence of vibration. It can be said that it is a place.

Based on the data of the image CPG1 of the stress distribution when the vibration of the first condition occurs, the stress characteristic measuring device 30 detects a point (for example, point D ) are selected, and a plurality of (eg, three) points (eg, points A, B, and C) having a large stress gradient among the pixel values are selected. Processor 35 is an example of a selection unit. The stress characteristic measuring device 30 measures the stress value P1D of the point D corresponding to the occurrence of the vibration under the first condition, and the stress values P1A, P1B and P1C of the points A, B and C corresponding to the occurrence of the vibration under the first condition. are plotted on the stress characteristic graph.

Next, the stress characteristic measuring device 30 measures the structure selected in the image of the stress distribution when the vibration under the first condition occurs based on the data of the image CPG2 of the stress distribution when the vibration under the second condition occurs. Stress values P2A, P2B, P2C . Select the P2D set. Stress profile measuring device 30 measures the selected stress values P2A, P2B, P2C . Plot the P2D on the stress profile graph.

Similarly, the stress characteristic measuring device 30, based on the data of the stress distribution images CPG3 to CPG5 when the vibrations under the third to fifth conditions occur, determines the A set of stress values (P3A, P3B, P3C, P3D) at points A, B, C, and D identical to points A, B, C, and D in the structure selected in the stress distribution image, the stress values ( P4A, P4B, P4C, P4D) and the set of stress values (P5A, P5B, P5C, P5D). The stress profile measuring device 30 measures the selected set of stress values (P3A, P3B, P3C, P3D), the set of stress values (P4A, P4B, P4C, P4D), the set of stress values (P5A, P5B, P5C, P5D). are plotted on the stress characteristic graph.

At points A, B, and C other than point D, which is a flat portion in the structure (in other words, a point where the amount of stress gradient change is small even if the magnitude (amplitude) of vibration changes) , the correlation (slope) between the magnitude of vibration (amplitude) and the stress value received is calculated. Specifically, the stress characteristic measuring device 30 derives the characteristic of the stress value based on the magnitude (amplitude) of the vibration at the point A as the slope when fitted with a straight line CVA of a linear function, for example. Similarly, the stress characteristic measuring device 30 derives the characteristic of the stress value based on the magnitude (amplitude) of vibration at each of the points B and C as the slope when fitted with, for example, the straight lines CVB and CVC of the linear functions. do. As a result, the stress characteristic measuring device 30 uses a plurality of stress distribution images obtained when a plurality of vibrations having different magnitudes (amplitudes) are applied to the structure at different timings, thereby measuring the stress distribution in the structure. It is possible to quantitatively derive with what kind of characteristics stress is applied to a portion where stress is likely to be concentrated, depending on the magnitude (amplitude) of vibration.

<Operation of stress characteristic measurement system>
Next, an operation procedure of the stress characteristic measurement system 100 according to Embodiment 1 will be described with reference to FIGS. 11 and 12. FIG. 11 and 12 are flowcharts showing the operation procedure of the stress characteristic measuring device 30 according to the first embodiment. 11 and 12, various processes are mainly executed by the processor 35 of the stress characteristic measuring device 30. FIG.

In FIG. 11, as an initial setting, the position of a reference point (that is, a reference value) detected based on the captured image from the visible light camera 10 or the data of the sensing result from the sensor 40 is set by the operation of the user using the operation unit 37. (St1).

Here, the position of the reference point includes the position on the platform when the infrared camera 20 starts taking the thermal image and the position on the platform when the infrared camera 20 finishes taking the thermal image. OK. The position on the platform when the thermal image is started is the end (for example, the right end or the left end) within the angle of view of the visible light camera 10 or within the sensing area of the sensor 40. For example, the leading car of the train is the image. It is the first appearing position within the corner or within the sensing area. On the other hand, the position on the platform when the thermal image capturing is finished is the end (for example, the left end or the right end) within the angle of view of the visible light camera 10 or within the sensing area of the sensor 40. This is the position where the vehicle appears last within the angle of view or within the sensing area.

Based on the timetable of the station STA stored in the memory 34, for example, and the captured image from the visible light camera 10, the stress characteristic measuring device 30 determines the type of train that can appear in the captured image (St2). The stress characteristic measuring device 30 acquires the data of the captured image from the visible light camera 10 or the data of the sensing result from the sensor 40 (St3).

Based on the determination result of step St2, the stress characteristic measuring device 30 determines that the train shown in the captured image acquired in step St3 is a train of a type that passes the station STA, and is the first train set in step St1. It is determined whether or not the reference point has been passed (St4). Here, the first reference point in step St4 is a reference point for causing the infrared camera 20 to start capturing a thermal image. ( St4, NO): The processing of the stress characteristic measuring device 30 waits until the train reflected in the captured image is of a type that passes through the station STA and passes the first reference point set in step St1.

On the other hand, when the stress characteristic measuring device 30 determines that the train reflected in the captured image is of a type that passes through the station STA and has passed through the first reference point set in step St1 (St4, YES ), instructing the infrared camera 20 to start capturing a thermal image of the structure (St5). The stress characteristic measuring device 30 acquires thermal image data sent from the infrared camera 20 based on the instruction in step St5 (St6).

The stress characteristic measuring device 30 determines whether or not the train that passed the first reference point in step St4 passed the second reference point set in step St1 (St7). Here, the second reference point in step St7 is a reference point for causing the infrared camera 20 to finish capturing a thermal image. When the train that has passed the first reference point has not yet passed the second reference point (St7, NO), the train in the captured image passes the second reference point set in step St1. The processing of the stress characteristic measuring device 30 waits until .

On the other hand, when the stress characteristic measuring device 30 determines that the train reflected in the captured image has passed the second reference point set in step St1 (St7, YES), the end of the capturing of the thermal image of the structure is indicated by the infrared ray. An instruction is given to the camera 20 (St8). The stress characteristic measuring device 30 acquires thermal image data sent from the infrared camera 20 based on the instruction in step St5 (St9). Further, the stress characteristic measuring device 30 derives the amount of temperature change due to the vibration generated in the structure due to the passage of the train, based on the acquired thermal image data (St9).

In FIG. 12, the stress characteristic measuring device 30 obtains the stress distribution based on the temperature change amount for each pixel derived in step St9, thereby generating an image of the stress distribution having the stress value as the pixel value for each pixel. (St10). The stress characteristic measuring device 30, from the data of the stress distribution image obtained in step St10, selects a plurality of points (for example, points A, B, and C) having the highest stress gradient among the pixel values (for example, three points). A stress value is selected and acquired (St11). Alternatively, the stress characteristic measuring device 30 selects and acquires the stress values of the same points as the previously selected high-ranking points (St11).

The stress characteristic measuring device 30 selects the stress value of a point (for example, point D) with a small (minimal) stress gradient among the pixel values in the image from the stress distribution image data obtained in step St10. (St12). The stress characteristic measuring device 30 converts the stress characteristic graph (see FIG. 10) into a stress characteristic graph (see FIG. 10), in which a set of stress values of a plurality of high-ranking points where stress concentration is likely to occur and stress values of points with a small stress gradient obtained in steps St11 and St12. (St13).

The stress characteristic measuring device 30 determines whether or not a predetermined number or more of sets of stress values have been plotted on the stress specific graph in step St13 (St14). If the predetermined number or more of sets of stress values are not plotted on the stress identification graph (St14, NO), the process of the stress characteristic measuring device 30 returns to step St2, and the predetermined number or more of the sets of stress values are plotted as stress values. The process from step St2 to step St14 is repeated in the stress characteristic measuring device 30 until the graph is plotted.

On the other hand, when the stress characteristic measuring device 30 determines that a predetermined number or more of stress values have been plotted on the stress characteristic graph in step St13 (St14, YES), the stress at each point plotted on the stress characteristic graph A correlation characteristic (specifically, a slope of a straight line) for each point (location) is derived using the data of the value pairs (St15).

Further, when the stress characteristic measuring device 30 detects that any straight line (for example, the straight line CVA) in the stress characteristic graph is selected by the user's operation, the information of the slope derived in step St15 and the information of the slope are stored in the memory 34. Using the prepared risk presentation table (see above), the risk at a point (place) in the structure corresponding to the slope of the selected straight line is identified. The stress characteristic measuring device 30 ranks the degree of risk among a predetermined number of ranks and displays the result on the display unit 36 (St16).

Furthermore, the stress characteristic measuring device 30 uses the information on the degree of risk identified in step St16 and the improvement plan presentation table (see above) stored in the memory 34 to determine points in the structure corresponding to the degree of risk. The improvement measures (countermeasures) for (place) are displayed on the display unit 36 (St17).

As described above, in the stress characteristic measuring system 100 according to the first embodiment, the stress characteristic measuring device 30 measures the stress characteristic generated in the structure (for example, the support fitting SPT1 including the three bolts V1 to V3). The stress characteristic measuring device 30 corresponds to a second communication unit 32 that acquires a plurality of thermal images taken at different times according to the surface temperature of the structure from the infrared camera 20, and to each of the plurality of thermal images. and a processor 35 for generating a stress distribution image to be applied. In each stress distribution image, the processor 35 calculates the stress value of point D (first portion) where the stress gradient is smaller than a predetermined value, and points A, B, and C (second portions) where stress is concentrated. , and using the obtained stress value of point D and the stress values of points A, B, and C, a portion of the structure (for example, at least one of points A, B, and C ) is derived and output.

As a result, the stress characteristic measuring device 30 can detect the infrared camera 20 even in an actual site environment where structures such as the support bracket SPT1 for supporting the premises speaker SPK1 are arranged (for example, the ceiling of the platform of the station STA). Based on the thermal image from the platform, it is possible to easily measure the stress on the structure caused by the vibrations generated by each passing train on the platform. In addition, unlike the stress measurement using a conventional strain gauge, the stress characteristic measuring device 30 can photograph even a narrow structure that does not have an area for bonding a strain gauge with the infrared camera 20. The stress distribution can be easily and conveniently obtained from the thermal image. In addition, the stress characteristic measuring device 30 obtains a plurality of stress distributions according to a plurality of types of vibrations having different magnitudes (amplitudes) applied to the structure, in order to support stress comparison for each part of the structure. Using the stress value at the portion where stress is likely to concentrate and the stress value at the flat portion where the stress gradient is small, the stress correlation characteristic can be measured with high accuracy and convenience. By being able to grasp this correlation characteristic, the stress characteristic measuring device 30 can determine which of the locations in the structure where stress is likely to concentrate is subject to strong stress, and which location has a longer life as a characteristic of the structure. It is possible to allow the user to easily determine whether or not it is likely to be shortened.

Further, in the stress characteristic measurement system 100, the visible light camera 10 or the sensor 40 is used to detect the occurrence of vibrations (in other words, the factors that cause the vibrations) that occur at the location of the structure (for example, the ceiling of the platform of the station STA). events) are detected. For example, this event corresponds to a train passing through the platform of the station STA. The infrared camera 20 captures and generates a thermal image in response to an instruction from the stress characteristic measuring device 30 each time vibration is detected at the location where the structure is arranged. As a result, the stress characteristic measuring device 30 can generate a stress distribution image applied to the structure at the timing necessary for obtaining highly accurate correlation characteristics of stress at each location of the structure.

In the stress characteristic measuring system 100, the stress characteristic measuring device 30 detects the occurrence of vibrations with different amplitudes (magnitudes) at least three times, and for each stress distribution image generated based on the detection of the occurrence of each vibration. The correlation characteristic is derived using the stress value of the point D selected in , and the stress values of the points A, B, and C where stress concentration is likely to occur. As a result, the stress characteristic measuring device 30 performs a linear function or the like from a set of plots of the stress value of the point D selected for each stress distribution image and the stress values of the points A, B, and C where stress concentration is likely to occur. Since the fitting accuracy can be improved, highly accurate correlation characteristics can be derived.

Further, in the stress characteristic measuring system 100, when acquiring the stress values of the points A, B, and C, the stress characteristic measuring device 30 selects from among the plurality of stress concentrated portions in each of the plurality of stress distribution images Acquire the stress value at the same location. As a result, the stress characteristic measuring device 30 can easily compare the degree of change in stress received due to vibration in the structure at the same location, so that it is possible to assist the user in determining whether or not the same location has deteriorated over time. .

In the stress characteristic measuring system 100, the stress characteristic measuring device 30 determines the condition of the structure based on the result of deriving the correlation characteristic (for example, the slope of the straight line of the linear function used for fitting). As a result, the user can easily determine whether or not there is a dangerous place where stress tends to concentrate in the structure.

Also, in the stress characteristic measuring system 100, the stress characteristic measuring device 30 presents countermeasures for the structure based on the determination result of the situation of the structure. As a result, the user can easily determine whether or not to take technical countermeasures (for example, repairs) for locations in the structure where stress is likely to be concentrated.

Various embodiments have been described above with reference to the drawings, but it goes without saying that the present disclosure is not limited to such examples. It is obvious that a person skilled in the art can conceive of various modifications, modifications, substitutions, additions, deletions, and equivalents within the scope of the claims. are within the technical scope of the present disclosure. In addition, the constituent elements of the various embodiments described above may be combined arbitrarily without departing from the gist of the invention.

In the first embodiment described above, as an example of the structure, the support bracket SPT1 (see FIG. 1) for the premises speaker SPK1 arranged so as to be fixed to the ceiling of the platform of the station STA was exemplified. It is not limited to the metal fitting SPT1. For example, the structure may be a train body. The car body of a train is subject to vibration during running, and there is a possibility that the number of passengers varies depending on the time zone such as commuting hours, or that passengers are unevenly distributed in a specific car (car number). Therefore, it is highly advantageous to obtain correlation characteristics for each part of the car body from the stress distribution image applied to the car body of the train.

Also, the structure may be a heavy machine such as a crane. A heavy machine such as a crane is subject to vibration during travel, and the stress that the tip arm receives may vary depending on the weight of a load such as soil to be transported. For this reason, it is highly advantageous to obtain the correlation characteristic for each location of the tip arm portion from the stress distribution image applied to the tip arm portion of a heavy machine such as a crane.

The structure may also be a bridge provided between piers supporting a highway. Bridges are subject to vibrations caused by vehicles (general vehicles, trucks, etc.) running over them, and the stresses received may vary depending on the weight of the vehicles running over the bridges. For this reason, it is highly advantageous to obtain the correlation characteristics for each location of the bridge from the stress distribution image applied to the bridge.

In addition, the structure is not limited to fastening portions such as bolts V1 to V3 for screwing the support metal fitting SPT1 to the beam portion JST1. or a connection formed on the basis of gluing. This is because, regardless of whether the fastening portion is formed by welding or adhesion, the bolts V1 to V3 according to the first embodiment are subject to vibration and stress as trains pass by.

In addition, in Embodiment 1, an example in which the external load applied to the structure is not constant (in other words, the magnitude (amplitude) of vibration is not constant) has been described. The magnitude (amplitude) of vibration need not be known. In other words, even when the load due to the external load is constant and unknown, the stress characteristic measuring apparatus 30 according to Embodiment 1 can similarly measure (evaluate) the stress characteristic.

The present disclosure provides a stress characteristic measuring method, a stress characteristic measuring apparatus, and a stress characteristic measuring method, a stress characteristic measuring apparatus, and a stress characteristic measuring method for highly accurate and convenient measurement of stress characteristics for comparison of stress generated at each location of a structure in an actual site environment where the structure is arranged. It is useful as a characteristic measurement system.

2 Internet 10 Visible light camera 20 Infrared camera 30 Stress characteristic measuring device 31 First communication unit 32 Second communication unit 33 Third communication unit 34 Memory 35 Processor 36 Display unit 37 Operation unit 38 Fourth communication unit 40 Sensor 100 Stress property measurement system CPG1, CPG2, CPG3, CPG4, CPG5 Images P1A, P1B, P1C, P1D, P2A, P2B, P2C, P2D, P3A, P3B, P3C, P3D, P4A, P4B, P4C, P4D, P5A, P5B , P5C, P5D Stress values SPK1, SPK2 Premises speaker SPT1 Support fittings V1, V2, V3 Bolts

Claims (9)

A method for measuring characteristics of stress generated in a structure, comprising:
acquiring a plurality of thermal images taken at different times according to the temperature of the surface of the structure from a first imaging device;
generating a stress distribution image corresponding to each of the plurality of thermal images;
obtaining a stress value of a first portion having a stress gradient smaller than a predetermined value and a stress value of each of a plurality of second portions where stress is concentrated in each of the stress distribution images;
using the obtained stress value of the first portion and the stress value of each of the plurality of second portions to derive a stress correlation characteristic of the portion of the structure ;
the correlation characteristic is a comparison of the stress value of the first portion and the stress value of the second portion;
Stress property measurement method. The correlation characteristic is the slope of a straight line connecting the comparison of the stress value of the first portion and the stress value of the second portion for each different vibration.
The stress measurement determination method according to claim 1. further comprising the step of detecting the occurrence of vibration occurring at the location of the structure with a second imaging device or sensor;
In the step of generating the plurality of thermal images,
generating the plurality of thermal images each time an occurrence of the vibration is detected at the location of the structure;
The method for measuring stress characteristics according to claim 1. In the step of deriving the correlation characteristic,
Occurrence of the vibrations having different amplitudes is detected at least three times, and the stress value of the first portion and the plurality of second stress values are selected for each of the stress distribution images generated based on the detection of each occurrence of the vibrations. deriving the correlation property using the respective stress values of the parts;
The method for measuring stress characteristics according to claim 3 . In the step of obtaining the stress value,
In each of the stress distribution images, the plurality of second portions are the same location,
The method for measuring stress characteristics according to claim 1. determining the condition of the structure based on the derivation result of the correlation characteristic;
The method for measuring stress characteristics according to claim 1. further comprising the step of presenting countermeasures for the structure based on the determination result of the situation of the structure;
The method for measuring stress characteristics according to claim 6 . A stress characteristic measuring device for measuring the characteristics of stress generated in a structure,
a communication unit that acquires a plurality of thermal images taken at different times according to the temperature of the surface of the structure from a first imaging device;
a generator that generates a stress distribution image corresponding to each of the plurality of thermal images;
a selection unit that acquires the stress value of a first portion having a stress gradient smaller than a predetermined value and the stress value of each of a plurality of second portions where stress is concentrated in each of the stress distribution images;
a computing unit that derives a correlation characteristic of stress in a portion of the structure using the acquired stress value of the first portion and the stress value of each of the plurality of second portions ;
the correlation characteristic is a comparison of the stress value of the first portion and the stress value of the second portion;
Stress property measuring device. a stress characteristic measuring device for measuring the characteristics of stress generated in a structure;
and a first imaging device,
The stress characteristic measuring device is
Acquiring a plurality of thermal images with different imaging times according to the temperature of the surface of the structure from the first imaging device;
generating a stress distribution image corresponding to each of the plurality of thermal images;
In each of the stress distribution images, obtaining a stress value of a first portion having a stress gradient smaller than a predetermined value and a stress value of each of a plurality of second portions where stress is concentrated,
using the obtained stress value of the first portion and the stress values of each of the plurality of second portions to derive stress correlation characteristics in portions of the structure ;
the correlation characteristic is a comparison of the stress value of the first portion and the stress value of the second portion;
Stress property measurement system.

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